Consider a locus in which the fitness of AA and Aa genotypes are greater than the fitness of aa genotype.In addition,this locus experiences forward mutation from the A allele to a allele.At this locus,the A allele will
A)always go to fixation.
B)always be lost.
C)never go to fixation.
D)never change.
E)None of the above

Question

Quizplus · Accepted Answer

Since the fitness of AA and Aa genotypes are greater than the fitness of aa genotype, the A allele will be selected for and increase in frequency within the population. However, the presence of forward mutation from A to a allele means that aa genotype could still arise. As aa genotype has lower fitness, it is likely to be selected against and decrease in frequency, but the A allele may not reach 100% frequency (i.e. fixation) because the a allele can still be produced via mutation. Therefore, the A allele will never go to fixation.

Consider a Locus in Which the Fitness of AA and Aa